This is a note to let you know that I've just added the patch titled dm bufio: subtract the number of initial sectors in dm_bufio_get_device_size to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dm-bufio-subtract-the-number-of-initial-sectors-in-dm_bufio_get_device_size.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a14e5ec66a7a66e57b24e2469f9212a78460207e Mon Sep 17 00:00:00 2001 From: Mikulas Patocka <mpatocka@xxxxxxxxxx> Date: Tue, 23 Feb 2021 21:21:20 +0100 Subject: dm bufio: subtract the number of initial sectors in dm_bufio_get_device_size From: Mikulas Patocka <mpatocka@xxxxxxxxxx> commit a14e5ec66a7a66e57b24e2469f9212a78460207e upstream. dm_bufio_get_device_size returns the device size in blocks. Before returning the value, we must subtract the nubmer of starting sectors. The number of starting sectors may not be divisible by block size. Note that currently, no target is using dm_bufio_set_sector_offset and dm_bufio_get_device_size simultaneously, so this change has no effect. However, an upcoming dm-verity-fec fix needs this change. Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> Reviewed-by: Milan Broz <gmazyland@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/md/dm-bufio.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -1463,6 +1463,10 @@ EXPORT_SYMBOL_GPL(dm_bufio_get_block_siz sector_t dm_bufio_get_device_size(struct dm_bufio_client *c) { sector_t s = i_size_read(c->bdev->bd_inode) >> SECTOR_SHIFT; + if (s >= c->start) + s -= c->start; + else + s = 0; if (likely(c->sectors_per_block_bits >= 0)) s >>= c->sectors_per_block_bits; else Patches currently in stable-queue which might be from mpatocka@xxxxxxxxxx are queue-4.19/dm-bufio-subtract-the-number-of-initial-sectors-in-dm_bufio_get_device_size.patch